brewer



Dec. 17, 1929., J. F. BREWER DRAWING BOARD 2 Sheets-Sheet Filed Jan. 15,1928 1N V EN TOR.

Dec. 17, 1929. J. F. BREWER DRAWING BOARD Filed Jan. 13, 1928 2Sheets-Sheet Waff@ INVENTOR.

BY xL# 7g4/M; 6m #6M/JW ATTORNEYS.

Patented Dec. 17, 1929 PATENT OFFICE JAMES F. BREWER, OF WASHINGTON,DISTRICT F COLUMBIA DRAWING BOARD Application filed January 13, 1928.

This invention relates to writing or draw ing boards such as may be usedin place of the customary blackboard.

One of the main objects of the invention is to devise a writing ordrawing board of this character, which shall be absolutely dustless. Afurther object is to provide a board from which the writing or drawingcan be quickly` and completely erased when desired, leaving the surfacein its original condition. Still another object is to provide a drawingboard which may have a white surface, as distinguished from the darksurfaces commonly employed. As a result of such white surface, thedrawing or writing may be done in different colors, blended or combinedas desired.

To the above ends, the invention eontemplates a drawing or writingsurface which is maintained damp or moist, and on which the lines may bemade by means of sticks or crayons of water-color pigment. The writingsurface itself is of such a nature that the pig ment does not penetrateit, but may be readily removed or erased by means of a soft wet pad orthe like.

In order that the invention may be readily understood, reference is hadto the accompanying drawings, forming part of this specification, and inwhich Figure 1 is a front view of my improved drawing board, the samebeing shown as mounted upon an easel;

Figure 2 is a side elevation thereof, parts being broken away;

an enlarged scale, substantially on the line 3 3 of Figure 1;

Figures 4 and 5 are a fragmentary side elevation and edge viewrespectively showing the construction of one corner of the frame. whichI employ;

Figures 6 and 7 are side and end elevations respectively, showing theconstruction of another corner of'such frame;

Figure 8 is a fragment-ary View of a slight modification Figure 9 is arear elevation of the upper member of my improved frame, showing a 5Dwater reservoir carried thereby;

Figure 3 is a vertical transverse section on seran No. 246,477.

Figure 10 is a rear elevation of my improved drawing board showing theframe partly removed therefrom;

Figure 11 is a fragmentary side View of a portion of the supportingeasel; Figure 12 is a view illustrating different means by which themarking material may be applied to the board;

Figures 13 and 14 are side and end elevations respectively of a blottingor absorbent pad which I may employ to remove surplus water; and

Figure 15 is a side elevation of an eraser for removing the marks orlines from the board.

In the following description and claims,

I shall use the term drawing board as a generic term designating aboard, slab, sheet or other support on which drawings, writing, or marksof any description can be made.

Referring to the drawings in detail, I preferably form my improveddrawing board proper, of a body or slab of some rigid porous materialsuch as unglazed earthenware, plaster' of Paris, natural stone orartificial 75 stone made from hydraulic cement or the like mixed withsuitable materials. By the word porous I mean that this slab or bodymust be permeable to a liquid such as water, so that water applied toone part thereof will spread or diffuse itself throughout the mass.

I have found, in practice, that an excellent slab can be prepared bymolding plaster of4 Paris upon a glass sheet, rubbed with a lightcoating of a solution of paraffin or the like to prevent sticking. Whenthe plaster of Paris has set and is removed from the glass, it will befound to have a very smooth hard surface, capable of being marked orwritten upon in the manner hereinafter described. Possibly in some casesit may be necessary to lightly sandpaper the smooth surface of such aslab in order to remove the glaze and open the pores. It is desirable,however, in preparing such a porous slab, that its surface should not beso porous that the pigment will permeate the same. In order to avoidthis excess porosity, I have found it sometimes desirable to apply tothe surface a filler such as a thin solution of shellac, resinousmaterial, varnish, enamel, or the like. The object of such filler is notto completely seal the pores of the slab, but to regulate the porosityto the desired extent, until just the proper degree of permeability isobtained.

In the drawings, the numeral l designates a porous slabsuch as I havedescribed, and it is preferably' molded in' rectangular for-m, as shown.In some cases, if desired,in order to give additional strength, theslabm'ay'be" reinforced, as indicated at 1ya in" Figure",A 8- by' meansof wire mesh lb or the like, of rust proof material.

After the slab has been prepared, itk is preferably mounted in a'rectangularmetallic frame. This frame comprisesa bottom member 2', sidemembers 3 and 4 hinged tov the bottom meml'i'er as at 5', and a topmember 6. All of these members are Uf'sh-aped' in cross section, asshown in Figure 3, andthe upper member @which isbodily removable fromthe other members, is, preferably secured to the members Sand' 4 by themeans shown in Figures 6 and 7 .l Referring to these gure's, it will beseen that, the ends of the sides of the member 6A are extended andben'tvaround the edge of" the member 3` (or 1l) as shown at 6n in Figure Theupper portion of these bent over ends is cut away to provide av slot,and through vthis slot projects a lug. or tongue 3 formed at the `endoffV the outer edge lo' the!y member 3. This. makes ai rigid interlockedconnection.4 Other methods of constructing and assembling. the framecan' 'T of course be employed" without departing from the spirit of theinvention. Behind the slab or` boardproper, I provide ai backing. whichis preferably formed of sheet metall.v This Abackingl isf designated bythe numeral 7,. an'd is best' shown in' Figure It is prefen ably pressedinto the shape of a shallow pani having marginal edgeportionsfa,disposed inY a pla-ne parallel'-y to but o'ii'set from 'thel plane ofthebody or bottom, and. connected therewith by sloping or inclinedintermediate portions Tb". A packing or gasket vofsoft rubber l,orthelike isjinterposed between the slab l andI the edges T of the backing orpan, as. showin in Figure 3, 'andthe whole is. then set in vthe abovedescribed' frame,` the inclined.

portions 7l abutting againstm'the edgerofiheframe and; causing. thegasket Sto. be clamped between .the slab4 and edge off the backing.-

In addition to the gasket 8 softrubber. striiis orfcushions 9 are placedin the bottom of each.

of thevframe nicmbe'rsf2,.3, 4, and than di wlnen` the slab and backing.are mounted zin the frame, and'I the lframe members assembled?. and.lockedtogetheras described, these soft rubber Astrips are strongly.compressedand bear tightly ,against the edgesofhthe' slab, so as.

to constitute a seal to prevent leakage or. Y t

. acquired at the time of yplacingit inthe sealed'` seeping oli thewater from-fthe slab..

Thespace between the slab 1 andthe bac`king.y 7', is preferably filledwith a mass of absorbent material, such as loose blotting paper or thelike, and this constitutes a diffusing pad which serves to absorb thewater applied as hereinafter described and dis# tribute it over the rearsurface of the slab or drawing board.

wIn order to supply water to the absorbent dilfusing pad,f[ provide awater reservoir 11, preferably of elongated'cylindricalform, and

mount this in brackets 12, secured to the upper.' frameimembenb 1rllhi's'.water reservoir is provided with a filling opening 13 and witha downwardly directed discharge nipple 14. A similar nipple lgis setinto the rear of the' pan' or'backing 7, near its upper edge, and ashort piece of rubber tubing 1-6 or. the

like is fitted over thef'tw nipples and serves.

to conduct" water from the reservoir tothe difl'usingpadbetween theslab.J pinch cock 1'7", shown in Fig-lure 9, or other suitableregulating deviceg'may be used lt'o lcont'rol the How of water asdesired; 1

The dra-wing` boardV above described'Y may conveniently be mounted in asupporting traine or easel, as best showny in Figure 1`.

To. this end,.t-runnions l8,.t-h'readed at their outer endsare `securedto 'the side members 3 and l of the fframe,and 'are adapted to rest innotches. I9 formed at the upperv ends-of' a pair of vertical framemembers 20. These are provided with extendedffeet or p'ede'stals drawingboard, as4 above described',V I may? conveniently employ crayons madeofL suit'- able water-color pigments. are ofcourse Water soluble,.-andIthey werk best when so treated asto be. relatively soft.. This may bedone incorporating; with 'the Pigment Some nonfhardning water gehaltbindersuch as glycerine. x I.have.found,;hoiv

ever, that water-color pigment. may be formed into sticks. or crayons'of the desired hardness by the following simple method. Pigmentin thecommercial form known asfpan. water color is first. subjected to theaction o'fmois.- ture until it becomes soft. Itis their moldedinto theform-of the desired crayon. Upon standirig, such crayon graduallyhardene..

When. the. desired degree off hardness isl reached, the crayon isthenplaeed: in abottlev and tightly closed. by meansV ofA a rubberstopper or. the like. .Y en4 it hasy reirlainedL in= this conditionfforsometime, the. pigment appears to set andfthereafter retainsindefinitely the same degree of' hardness which vi had bottle; Y While Ihave described the above m'etl'o'dI These crayons" of formingwater-color crayons, I do not wish to be limited to such method, asother successful methods will readily suggest themselves to thoseskilled in the art.

These crayons may be made with blunt points as shown at 24 in Figure l2,or with more or less tapered points, as indicated at 26, and in eithercase, they are, in practice, preferably used in holders 25, in order toprotect them from the effect of handling. It is also quite possible toapply water-colors to my improved drawing board by means of an ordinaryartists brush such as indicated at 27 in Figure l2.

The drawing board having been constructed of a slab of the properporosity and mounted in the frame and supplied with water, as described,can be readily written or marked upon by means of the water-colorcrayons referred to. It is only necessary to apply the crayon to theboard with a very light touch. The contact of the water-color pigmentwith the wet surface of the board results immediately in dissolving thepigment at the extreme tip of the crayon, and as the crayon is movedalong, this dissolved water-color is deposited on the surface of theboard, leaving an exceptionally brilliant mark. For the making ofpictures and the like, these sharp bright lines may be shaded or blendedby means of a brush or other instrument, as desired.

The effect is particularly pleasing because of the fact that, when usingplaster of Paris, the surface of the board is substantially white, thusgiving full value t0 the different colors which may be employed.

A valuable and striking feature of my invention resides in the fact thatthe brilliant lines and colors produced, as above described, can becompletely erased with exceptional ease. All that is necessary is tolightly rub the surface of the board with a soft pad of raw cotton orthe like, which has been moistened with water. A desirable eraser forthis purpose is shown in Figure l5, in which 30 designates the cottonpad. This is conveniently enclosed within a cloth cover 3l, held on by asuitable band 32.

The application of the wet cotton pad to the surface of the drawingboard results in immediately and completely washing off thewater-colors, leaving the surface clean and white as before.

If, as a result of the erasing operation, or, for any other reason, thesurface of the board should be covered with an excessive amount ofwater, this may be removed by applying the absorbent pads of blottingpaper or the like, such as shown at 28, 29 in Figures 13 and 14.

lVhile it is possible to obtain good results with a bare porous slab, asdescribed, I have found that even better results can be obtained byplacing upon the surface of such a slab a specially selected sheet ofthin flexible material, pervious to water. Various kinds of so-calledwater-proof and other hard finished paper may be employed for thispurpose, but I have discovered that perhaps the best results areobtained by using certain types of viscose. A commercial form of thismaterial is known as cellophane, and consists of an exceptionally thin,tough and transparent sheet. It does not disintegrate under the actionof water and its surface is extremely smooth. Although ordinarilyregar-ded as waterproof, it nevertheless appears to be porous, sincewater readily permeates through it.

Such a sheet may, if desired, be cemented on the surface of the slab. Ifind it preferable, however, to simply lay the sheet upon the slab,where it is held in position merely by the viscosity of the water. Whendampened, it becomes exceedingly soft and pliable, and may be smoothedout upon the slab where it will adhere so closely as to be almostinvisible. At the same time, the sheet can be readily stripped oflI andremoved, should it become worn or marred, and thus thedrawing surface.can be constantly renewed. sheet is indicated at 33 in Figures l and 3.

YWhile I have described the board as white, it is obvious that dye orpigment can be used for imparting to the slab any desired color.Moreover, the sheets of cellophane or the like which may be employed aremanufactured in different tints or colors.

l/Vhile I have. described a drawing board comprising a rigid slab, I donot wish to limit myself to this, since, where a sheet such as 33 isemployed, it is possible to support it upon a fibrous base or a slabformed, for eX- ample, of hard pressed wood pulp or cardboard, fiberboard, or the like.

From the foregoing, it will be apparent that I have provided an improveddrawing board on which brilliant lines or marks can be readily producedin any desired color and with a very light pressure, and from which suchmarks or lines may be easily and com pletely erased absolutely withoutdust, and it is thought that the many advantages of my invention will bereadily appreciated without further discussion.

lVhat I claim is 1. A drawing board comprising a porous body, and meansfor maintaining said body moist.

2. A drawing board comprising a smooth surfaced porous rigid slab, andmeans for maintaining said slab moist.

3. A drawing board comprising a porous body, and means for continuouslysupplying water to said body to keep it wet.

4. A drawing board comprising a porous slab having a front and a rearface, and means for feeding water to the rear face of said slab to keepthe front face moist.

5. A drawing board comprising a porous This slab xhavingn 'front :and a:rear twee, an 'absorbent diffusing padin cont-aotfw'i'ththe rear 'faceof said s1a.b,=and meansio'r-eedin'g Water to said'absorbent pad tolImrintaiI-i said 'slab in levfmoist Condition.

sab having a fi'ro'nt "rear f-faoefim absorbent diii'usingpadin 'Contactwith the rear face: of` .said slab, means 'for .feeding Water 'tosaid=pad,f=and:means for sealing the edges `of saidfslnbienfd fpadto.prevent the escape of Water therefrom.

'7. A `drzwingboard lcomprisinga porous slab having .a ffrontfund ,fayrear faee,an absorbent d'u-singpad in` Contact with the rear -feceo'said slab, meansforfeeding Water to -s'aid pad., rand it `frame inWhchvsaid 4slab and pad arellnounte'd, said frame having meanslfor.preventingthe escape of Water from the .edges o-fsaid slab ,andpad.

S` A drawin'gfboard comprising a porous lbody, drame in Which-said bodyis mounted, "a water reservoir 'Carried by saidframe, andineens.orsnpplyingwater from said reser- 'Voir to said porous body tomaintain the latter damp.

9. A dnaWi-ng board Comprising a rigid .poronsfbody, :aWater-perlineable sheet superfposedionthesurface of said body, and means.for 'mnintztiningsid body land sheet -in la moistA Condition.

10. lA drawingboardV'c'omprisngf'a porous body, a thin, ieXble-,vwterlnermeztble-sheet tcovering said body .and constituting the drawingsurface, and tmeans for supply-ing Water to fsai-'dlbodyand ksheettokeep them Wet.

Ill. drawingboardfcomprising a .porous stab, a' sneet'ofyiseosefsupeqbose'd upon 4said slab to constitute the drawing slrfaee,and means 'f'or maintaining vrstdfslztb and sheet in la moist Condition,

.A drawing" board comprising a rigid slab for ssul'aporthayin-g vasmooth lface, and :1- fsheet 'of i Viscose snperposed on and fadh'eringt-o `said smooth to constitute ithe dii-owing Ssurlfaoe.

InE testimony'fxyhereof 1I myl signature.

JAMES f1?. EBREWER.

